Galling-resistant threaded tubular component and process for coating said component

Abstract

A galling-resistant threaded tubular component for drilling or operating hydrocarbon wells includes at one of its ends a threaded zone produced on its external or internal peripheral surface depending on whether the threaded end is male or female in type, with at least one portion of the threaded zone being coated with a dry film with a crystalline structure with a high specific surface area principally constituted by one or more mineral salts which are not reactive towards metals, and a process for coating such a component using a dry mineral film with a crystalline structure having a high specific surface area principally constituted by one or more mineral salts which are not reactive towards metals.

The invention claimed is: 
     
       1. A process for coating a galling-resistant steel tubular component made of one or more metals for drilling or operating hydrocarbon wells, the tubular component including at an end thereof a threaded zone produced on one of an external or internal peripheral surface of the tubular component, depending on whether the end having the threaded zone is male or female in type, the process comprising:
 dissolving one or more mineral salts, which are not reactive towards the metals of the tubular component, in a solvent so as to form a solution; 
 pre-heating the threaded zone of the tubular component; 
 depositing the solution directly on at least a portion of a steel surface of the threaded zone after the pre-heating; and 
 evaporating off the solvent to obtain a dry film having a crystalline mineral structure having a high specific surface area and which is not reactive towards the steel of the tubular component, 
 wherein the specific surface area of the dry film having a crystalline mineral structure is more than 20 m 2 /g, 
 wherein the solution is an alkaline silicate dissolved in water, and 
 wherein the pre-heating the threaded zone of the tubular component includes heating the threaded zone between 50° C. and 250° C. before depositing the solution. 
 
     
     
       2. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the solution is deposited by spraying. 
     
     
       3. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the solution is deposited by dipping. 
     
     
       4. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the threaded zone is heated to between 50° C. and 300° C. after depositing the solution. 
     
     
       5. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the solution is deposited at a temperature slightly below a boiling point thereof. 
     
     
       6. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein before depositing the solution, the solution is supplemented with an anticorrosion agent. 
     
     
       7. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein before depositing the solution, the solution is supplemented with a braking additive constituted by dispersions of mineral or organic particles which have a relatively high cleavage load value and/or strong particulate interactions or attractive bonds between particles and/or a medium to high Mohs hardness and/or a rheological behavior which is resistant to or opposes movement, each braking additive being selected from a group including bismuth oxide, titanium oxide, colloidal silica, and carbon black. 
     
     
       8. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein before depositing the solution, the solution is supplemented with nanometric mineral particles to increase frictional resistance of the dry film by adjusting a coefficient of friction thereof. 
     
     
       9. The process for coating a galling-resistant steel tubular component according to  claim 8 , wherein the nanometric mineral particles include at least one of alumina, silica, TiN. 
     
     
       10. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein before depositing the solution, the solution is supplemented with fullerene particles to increase frictional resistance of the dry film by reducing a coefficient of friction thereof. 
     
     
       11. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein before depositing the solution, the solution is supplemented with an organic dispersion/emulsion. 
     
     
       12. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the threaded zone is coated with a lubricating system once the dry film has been formed. 
     
     
       13. The process for coating a galling-resistant steel tubular component according to  claim 12 , wherein the lubricating system is a hot-melt. 
     
     
       14. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the specific surface area of the dry film having a crystalline mineral structure is more than 100 m 2 /g. 
     
     
       15. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the pre-heating the threaded zone of the tubular component includes heating the threaded zone between 120° C. and 250° C. before depositing the solution. 
     
     
       16. The process for coating a galling-resistant steel tubular component according to  claim 1 , wherein the evaporating off the solvent includes post-heating the threaded zone of the tubular component after depositing the solution. 
     
     
       17. The process for coating a galling-resistant steel tubular component according to  claim 16 , wherein the post-heating the threaded zone of the tubular component includes heating the threaded zone between 50° C. and 350° C. after depositing the solution. 
     
     
       18. A process for coating a galling-resistant steel tubular component made of one or more metals for drilling or operating hydrocarbon wells, the tubular component including at an end thereof a threaded zone produced on one of an external or internal peripheral surface of the tubular component, depending on whether the end having the threaded zone is male or female in type, the process comprising:
 dissolving one or more mineral salts, which are not reactive towards the metals of the tubular component, in a solvent so as to form a solution; 
 pre-heating the threaded zone of the tubular component; 
 depositing the solution directly on at least a portion of a steel surface of the threaded zone after the pre-heating; and 
 evaporating off the solvent to obtain a dry film having a crystalline mineral structure having a high specific surface area and which is not reactive towards the steel of the tubular component, 
 wherein the specific surface area of the dry film having a crystalline mineral structure is more than 20 m 2 /g, and 
 wherein the solution is an alkaline silicate dissolved in water.